Hissing noise through headphones

[Alexs85]

Monitor arrived today and I can hear constant loud hissing noise through headphones (tried multiple ones, it's definitely the monitor that's faulty here). I have the monitor connected to my Lenovo V155 laptop. Don't currently have any speakers to test. Is there anything I can do to stop the hissing? I tried going through customer support but it didn't accept my serial number, so I can't get hold of them!

[savvy2]

what is your product code #? 4WH45AA#ABA ???????

how is MON connected to LEnovo,  all connections need to be told first.

the video cable DP or HDMI.?

and 3.5mm audio, cable. to PC or to monitor?

what phones are these, 3.5mm , usb or bluetooth. (I Guess 3.5mm phones)

the monitor does have 1 headphone-out;.  port, and so the HDMI or DP gpu card driver must support sound on DP or HDMI

even load newer driver on the Lenovo.

there is no volumn control in the OSD of the monitor, only on the PC. side. do so there first

the PC must have sound turned on for HDMI if using HDMI.

this is MS settings via the GPU driver in Lenovo.   

on my PC i click task bar speaker Icon, then click audio devices, then  pick  "nvidia output" or what you have for HDMI IDK

i have many outputs on my PC, and a USB DAC too. and all work , if I pick one. there. 

then turn up the volume next.

[Alexs85]

The monitor has two product numbers. 4WH45AA and 4WH45AS. The Lenovo is connected to the monitor via an HDMI cable. Headphones are plugged into the monitor. They're 3.5mm stereo headphones.

As for the HDMI settings, I can't find the settings you're describing 😕

But the sound does work on the monitor, it comes out clear, there's just also a hissing noise on top of it. When connecting the laptop to a TV with HDMI, there is no hissing. Also, the hissing happens when I connect a different laptop to the same monitor. Is this not maybe just a faulty monitor?